Jar



March 21, 1944. J. T. PHIPPS JAR Filed July 29, 1940 5 Sheets-Sheet lZZZ 6n 1Z- flzaz FIG. 20"..

Jo /v 7T Pym/ 5 INVENTOR ATTORNEY March 21, 1944. p pps JAR Filed July29, 1940 5 Sheets-Sheet 2 16. 4. .26. 4a. .FZ'G. 5. lZZ'G. 5a.

Joy/v TPH/PPS,

INVENTOR ATTORNEY J. T. PHIPPS March 21, 1944.

JAR

Filed July 29, 1940 FIG. 6a.

5 Sheets-Sheet 5 INVENTOR .EZZG. 7a.

day/v KPH/PA;

a y a? 521 ATTORNEY March 21., 1944. J. T. PHIPPS JAR 5 Shee'ts-Sheet 5Filed July 29, 1940 dofln/l'py/flps,

INVENTOR 5y ATTORNEY Patented Mar. 21', 1944 JAB John T. Phipps,Huntington Park, Calif., assignor to S. R. Bowen 00., Huntington Beach,Calif a corporation of California Application July 29, 1940, Serial No.348,138

16 Claims.

My invention relates to jars and has particular reference to Jarsemployed in connection with the drilling of deep wells for the purposeof producing a jarring blow upon tools or other devices which havebecome stuck in the well bore.

In the drilling and manipulation of deep wells, particularly oil wells,it frequently occurs that tools or other apparatus employed in the wellbore become stuck in the bore preventing the ready dislodging thereof bythe mere upward pull exerted upon the string of pipe or tubing uponwhich the tools are suspended. In such cases it is necessary to providea jarring or hammer- !ike blow in the pipe or tubing string in order todislodge the stuck tool or other device.

It also frequently occurs that in the manipulation of packers, testers,and other devices employed in the well that such devices become sosecurely fastened in the well as to require the use of jarringhammer-like blows to dislodge them.

Jars for this purpose have consisted essentially of a tool including ahammer element and an anvil element interconnected by some releasablemechanism which, when a predetermined lifting strain is placed upon thedrill string or a predetermined rotary movement is given to the drillstring, will be released to permit the hammer and anvil elements to moverelative to each other in the direction of the axis of the well bore andengage each other with a violent impact.

It has long been felt that the jarring blow most effective in themovement of such devices should be produced while a relatively greatlifting strain is imposed upon the stuck tool or fish, but heretoforeall of the jarring tools have been so constructed that, while an upwardstrain is taken upon the fish prior to the production of the jarringblow, the operation of the release mechanism to produce the jarring bloweffectively releases the upward strain which has been placed upon thefish.

It is therefore an object of my invention to provide a jar in which anupward strain of any desired value may be placed upon the fish and.

may be effectively and continuously maintained while the jarring blow orblows are produced,

Another object of my invention is to provide a jar in which a rigidconnection is maintained at all times between the drill string and thefish, and in which a jarring blow is produced upon the fish while apredetermined strain is maintained upon the fish through such rigidconnection.

It is also an object of my invention to provide a device of thecharacter set forth in the preceding paragraph wherein the upwardjarring blow is developed by a movable hammer adapted to be rapidlymoved into striking engagement with an anvil portion formed as a part ofthe means for effecting the rigid connection between the drill stringand the fish.

It is an additional object of my invention to provide a jar of thecharacter set forth in the preceding paragraphs wherein the hammer ismoved toward the anvil by means of a strong compression spring.

It is a still further object of my invention to provide a.jar of thecharacter set forth in the preceding paragraphs wherein a means isprovided for storing energy in the compression spring which drives thehammer and a means for releasing such stored energy to permit the springto move the hammer into striking engagement with the anvil.

It is also an object of my invention to provide a jar of the characterset forth hereinbefore wherein the energy which is stored in thecompression spring is derived from the well drilling fluid circulationpumps disposed at the ground surface and transmitted to the location ofthe jar by the wash opening provided in the drill string extendedbetween the ground surface and the jar.

it is a still further object of my invention to provide a jar of thecharacter set forth in the preceding paragraphs with a pressureresponsive means which operates to release the compression spring andallow the spring to force the hammer upwardly into striking engagementwith the anvil whenever the fluid pressure in the drill string rises toa predetermined value.

Another object of my invention is to provide a jar of the characterdescribed in which after the first jarring blow has been produced, thejar can be re-set for a repetition of blows without lowering the drillstring and without releasing the upward strain maintained upon the fishas distinguished from prior art constructions in which. it wasnecessary, not only to release the upward strain in order to re-set thejar for a second blow, but in fact required that considerable downwardforce be exerted upon the fish during the re-setting operation, thustending to aggravate the binding of the fish in the bore.

It is an additional object of my invention to provide a jar of thecharacter set forth hereinbefore which includes a means for repeatedlyactuating the hammer mechanism to cause a series of upwardly directedjarring blows to be struck without requiring that the steady upward pullon the fish be released or aim: ished.

It is a still further object oi my invention to provide a jarconstruction of the character set forth hereinbeiore wherein thepressure respon sive means which controls the action of the hammer isautomatically reset so that the jar will continue to strike upwardlydirected jarring blows at periodic intervals as long as the well fluidcirculating pumps are in operation.

Other objects and advantages oi my invention will be apparent from astudy of the following specifications. read in connection with theaccompanying drawings. wherein:

Fig. l is a fragmentary longitudinal vertical section of the upper halfof one form of iar constructed in accordance with my inventionillustrating the relative positions of the parts at the time aconnection is effected with the fish and prior to the initiating of anyjarring operations:

Fig. la represents a continuation of Fig. 1 and illustrates theconstruction of the lower half of the Jar:

Fig. 2 is a view similar to Fig. 1 but illustrates the relativepositions occupied by the parts after the well fluid circulation pumpshave been started to transmit energy to the jarring mechanism prearatory to striking a jarring blow;

Fig. 2a is a view similar to Fig. la and comprises a continuation ofFig. 2 illustrating the lower portion of the jar:

Fig. 3 is a cross sectional view taken substantially along the linel'lIIlI 01' Fig. l to illustrite the relative disposition of the partsemployed: Fig. 4 is a view similar to Figs. 1 and 2 but illustrating thepositions occupied by the parts at the time the pressure responsivemeans or control valve is released to permit the compression spring tomove the hammer portion oi the Jar upwardly to later effect an upwardlydirected jarring blow;

Fig. 4121s a view similar to Figs. 1a and 2a and represents acontinuation oi Fig. 4 to illustrate the lower portion of the jar;

Fig. 5 is also a view similar to Figs. 1 and 2 but illustrating therelative positions occupied by the parts at the time the hammer portionof the Jar is moved into striking relationship with the anvil portion.and illustrating the mannor in which the pressure responsive means orcontrol valve is re-set so as to permit a second arring blow to beproduced in the same manner as that employed for producing the firstjarring blow:

Fig. 5a represents a continuation of Fig. 5 to illustrate the lowerportion of the jar;

Fi 61s a view similar to Fig. 1 but illustratin a different embodimentof my invention, Fig. 6 illustrating the various parts in the positionsthey occupy at the time a connection is efiected with the flsh andbefore any attempt is made to develop a jarring blow;

Fig. 6a is a continuation of Fig. 6 and illustrates the construction ofthe lower half of the Jar, the upper half only being illustrated in Fig.6;

Fig. 7 is a view similar to Fig. 6 but illustrating the positionsoccupied by the parts after energy has been stored in the compressionspring and prior to the release of the energy to deliver a jarring blow:

Fig. 7a is a continuation of Fig. 7 illustrating ne ates the positionsoccupied by the parts disposed in the lower portion of the jar;

Fig. 8 is also a view similar to Figs. 6 and '1 but representing themanner in which the pressure responsive device or control device isreleased to permit the release of the hammer so as to later effect anupwardly directed jarring blow;

Fig. 8a is a continuation of Fig. 8 illustrating the lower portion ofthe jar;

Fig. 9 is also a view similar to Figs. 6 and 7 but illustrating thepositions occupied by the parts immediately prior to the striking of thejarring blow, the hammer being illustrated as having been moved part waytoward a position engaging the anvil portion of the Jar:

Fig. 9a is a continuation of Fig. 9 illustrating the positions occupiedby the mechanisms disposed in the lower portion of the .1 ar;

Fig. 10 is a fragmentary longitudinal sectional view illustrating amodified construction which may be employed on a jar of the characterillustrated in Figs. 6 through 9a; and

Fig. 11 is a View similar to Fig. 10 illustrating still anothermodification of my invention.

Referring to the drawings, I have illustrated in Figs. 1 and la one formof jar of my invention as including an elongated tubular housing iconnected as by means of threads 2 at its upper end to an adaptor member3 which carries a pin e permitting attachment thereof to the lower endof a drill string as by threaded engagement with a box portion 5 of atool joint half secured to such drill string. The lower nd of thehousing i may also be connected as by means of threads 6 to an adaptoror tool joint member 7 which defines a box 8 permitting the adaptor i tobe threadedly engaged with the pin portion 9 of a tool joint half 50,which latter tool joint half may be connected to an additional length orlengths of drill pipe and extended downwardly to the bit, fishing tool,or other device which is securely attached to the fish which is to beremoved from the well.

The lower adaptor i is preferably provided with a relatively smalldiameter wash opening H which, at its junction with the upper end of theadaptor l, defines a shoulder I2 upon which may be rested a large andstifi compression spring i3 which is enclosed by the housin i. Thecompression spring may have a length and spring constant as desired,depending upon th type of blow which the jar is intended to strike, thespring it being adapted to exert an upwardly .dlrected acceleratingforce on a hammer M which is slidably mounted within the housing I andrested upon the upper end of the spring l3.

The upper end of the hammer I4 is preferably provided with a strikingend which may be formed .as desired but which is preferably rounded asindicated at i5 in Fig. l to permit a reasonable amount of deformationthereof as a result of the blows struck without impairing the operationof the device. The striking and I5 is adapted to engage a similarlyformed striking portion or 'anvil i6 formed as an integral part of theupper adaptor 3.. The adaptor 3 is likewise provided with a fluidpassage or wash opening I! communicating with the conventionalcirculation pas sage provided in the drill string to which the device issecured so as to permit drilling fluid to be pumped from the groundsurface into the housing I.

In order that the pressure of the circulating fluid which may bepumpedinto the housing I through the wash opening II may be employed tocompress the spring I3, I prefer to form the hammer, I4 with alongitudinally extending bore II which carries in its upper end a valveconstruction I9 adapted to be moved between a position closing oi! thepassage I8, as is illustrated in Fig. 1, and a position opening suchpassage,

as is illustrated in Fig. 4. The valve construcindicated at 2I toreceive the sleeve 20 and to provide a shoulder 22 against which thesleeve 20 may be seated. The sleeve 20 may be secured within theenlarged bore 2| as by means of a threaded engagement such as thatindicated at 23 in Fig. 1.

The sleeve 20 is likewise provided with a longitudinally extending bore24 within which is slidably mounted a valve member 25, the slidablemovement of the valve member being limited to an upper position such asthat illustrated in Fig. 1 and a lower position such as that illustratedin Fig. 4 by suitable stop means which may comprise a pin 26 carried inthe sleeve 20 and extended transversely across the bore 24, the lowerportion of the valve member 25 being provided with slots 21 throughwhich the pin 25 is passed, the length of the slots 21 being so adjustedthat engagement of the ends of the slots with the pin ,26 will serve tolimit the movement of the valve member 25 in the above definedpositions. It will be observed that with the valve I! and the hammer I4in the positions illustrated in Fig. 1, the circulation passage throughthe jar is closed off by the valve 25 at the upper end of the hammer I4.

In order that operation of the mud pumps at the ground surface to forcefluid downwardly through the interior of the drill string will compressthe spring I3, I employ a construction wherein the wash opening IIterminates in an annular recess 28 having a diameter considerably inexcess of the diameter of the wash opening 21, fluid connection betweenthe recess 28 and the housing I being established by means of aplurality of smaller longitudinally extending bores 29 and 30, the outerones 29 of which are disposed a greater distance from the center of thehousin I than the radius of the valve member 25 so that the valve 25will not interfere with the wash opening. This construction permits thefluid which is pumped downwardly through the drill string by the mudpumps to be conveyed to the interior of the housing I at a point abovethe upper end of the hammer I4 with the result that the fluid pressuredeveloped thereby and exerted on the upper end of the hammer I4 willforce the hammer downwardly within the housing I and compress thecompression spring l3, the position of the hammer after such downwardmovement has taken place being illustrated in Fig. 2.

As soon as the hammer has been displaced a distance corresponding to themaximum force which it is desired to exert upon the spring I3, thepressure which has forced the hammer into that position should besubstantially instantly released to allow the spring I3 to impart anaccelerating force to the hammer I4 30 that it will be moved upwardlywith a high velocity so as to strike the anvil portion IS a severe blow.

The valve construction I9 above described includes a means which isresponsive to the pressure which is exerted by operation of the mudpumps upon the upper end of the hammer I 4 and causing the valve member25 to move to an open p sition to elect whal s ofthe hammer u. The valvemember 25 is accordingly preferably provided with an internal bore IIwhich extends upwardly from the lower end of the valve member to a pointcloselyadjacentthe upper end thereof so as to define a fluid. passageextending substantially the full length of the valve member 25 but notentirely therethrough. This fluid passage may be extended intocommunication with the exterior of the valve member 25 as by providing aplurality of ports 22 therein, these ports .being disposed in suchposition as to communicate with an annular recess or enlarged diameterportion 33 of the bore 24 which is' provided in the sleeve 20. Thus whenthe valve member 25 is moved to its lowermost position such as thatillustrated in Fig. 4, the fluid pressure which is exerted on the top ofthe hammer I4 may be released by flow of fluid downwardly through theupper end of the bore 24 past the head portion of the valve member 25and into the enlargement or recess 33. The path of the fluid fiow isfrom the recess 23, through the ports 32. into the bore II provided inthe valve member 25 and from thence downwardly and into the fluidpassage l8 which is provided in the interior of the hammer I4.

In order that the movement of the valve member 25 from the positionillustrated in Fig. 1 to the position illustrated in Fig. 4 may be maderesponsive to the fluid pressure existing in that portion of the housingdisposed above the upper end of the hammer I4, I prefer to provide aplurality of longitudinally extending slots 34 through the wall of thetubular portion of the valve member 25 so as to define a plurality oflongitudinally extending spring members, each of these members havingformed thereon an outwardly extending projection 35 adapted to bereceived in a corresponding recess 35 formed in the interior surface ofthe bore 24. The lower surface which defines the recess 36 is preferablyinclined inwardly and downwardly at a slight angle and the correspondingsurface of the projection 35 is preferably similarly inclined so thatwhen the downward force which is exerted upon the upper end of the valvemember 25 reaches a certain predetermined value, the inwardly directedcomponent thereof which is developed at the engagement between the twoaforementioned inclined surfaces will be suilicient to cause the springmembers which are defined by the slots 34 to be defiected inwardly adistance sufficient to cause the circle which is defined by the exteriorsurface of the projections 35 to be reduced to a diameter correspondingto the diameter of the bore 24.

When this condition obtains, the valve member 25 will be released fromits upper position and will be permitted to move downwardly under theurging of the fluid pressure exerted on the upper end thereof. Asaforementioned, this downward movement will be limited in the positionillustrated in Fig. 4 by the action of the pin 26 and slots 21.

The immediate release of fluid pressure from above the hammer I4 willpermit the spring I3 to drive the hammer I4 upwardly into violent impactwith the anvil I6. This impact will be transmitted through the housing Iand the lower adaptor I to the fish with which the jar is engaged so asto effect a loosening of such fish.

The preferred mode of operation of my device contemplates the exertionof a considerable upward force on the fish prior to the time the jar,

loosen the fish from whatever condition is causing the fish to be stuckwithin the well bore.

As soon as the blow is struck by the hammer,

it is necessary that the valve member 25 be moved from the positionillustrated in Fig. 4 back to a closed position, as is illustrated inFig. 1, in order to permit a second blow to be struck by the hammer.

The device of my invention-provides for an automatic re-setting of thevalve member 251 by means of the force developed by the inertia of thevalve member 25 at the time the hammer It comes into engagement with theanvil it. The valve member is therefore made of such weight as to causethe inertia force to be sufficient to overcome the sliding friction ofthe projections 35 on the walls of the bore 24 and move the valve memberupwardly to the initial position as is illustrated in Fig. 1. g

It will therefore be seen that the valve member is self-resetting sothat immediately upon the delivering of the jarring blow, all of themechanism is rastored to the positions occupied before any attempt tostrike was initiated, as is illustrated in Fig. 1. It therefore followsthat as long as the mud pumps at the ground surface are maintained inoperation, the above described be repeated so that it is possible toexert a steady upward pull on the fish while repeatedly strikingupwardly directed jarring blows, thus permitting the fish to begradually inched away from the cave-in or condition that is causing thefish to stick within the well bore.

The same cycle of operation and the same advantages may be obtained by aconstruction such as that illustrated in Figs. 6 through 9a. This deviceoperates on the same principle as the modification previously describedand accordingly includes a barrel 5|} connected as by means of threads5| to an upper adaptor 52, the adaptor 52 carrying a pin portion 53permitting attachment to the aforementioned tool joint half 5 comprisingthe lowermost end of the drill string. The lower end of the housing 50is similarly engaged as by means of threads 54 to a lower adaptor 55,this adaptor being provided with a box 56 permitting attachment to thepin portion 8 of the aforementioned tool joint half I form- ,ing a partof the connection between the jar =,and the fish.

As in the previously described modification, the lower adaptor 55 isprovided with a wash open- :ing 51 which, at its junction with the upperend of the adaptor 55, defines a shoulder 58 upon 'whicha strongcompression spring 59 may be adaptor I2 is provided with a wash opening63 assayed which may be enlarged as indicated at M to define a housingfor enclosing a valve spring 85. The valve spring 65 is adapted to exertan a stem portion d1 of which is mounted for alidable movement in aspider 88 secured as by means of threads 69 in an enlarged lower portionof the bore $4. The upper end of the valve stem 81 may carry a spiderill adapted to serve the dual purpose of effecting connection betweenthe valve spring 65 and the valve stem 81 and limiting the upwardmovement of the valve member 68 through engagement of the spider 15 witha shoulder H formed at the junction between the wash opening 63 and theenlargement 64 thereof. The spider Ill is preferably constructed in theform of a star or similar shape so as a establish a fluid connectionbetween the wash opening 83 and the valve spring housing 86 at the timethe spider 10 is engaged with the shoulder 1| and a fluid connectionbetween the valve spring housing 64 and the upper portion of the housing50 is preferably established as by providing a plurality of fiuidpassages 12 in the aforementioned lower spider 68.

The valve member 66 is adapted'to engage an annular seat 13 which isformed at the upper end of the hammer 60 by the intersection therewithof a longitudinally extending bore I4 which is formed in the hammer. Itwill be observed that the valve member 65 thus serves to close oh thefluid passage through the housing d at the top of the hammer 60 so thatwhen the mud pumps are started the pressure which is transmitted to theinterior of the housing 5d will be applied to the upper end of thehammer $0, and serve to move the hammer downwardly within the housing 60and compress the spring 59. It will also be noted that the pressurewhich is exerted on the upper end of the hammer do is also exerted onthe valve member 66 so as to tend to hold the valve member 66 in aclosed position and to tend to cause the valve member 56 6 to be moveddownwardly along with the hammer The valve spring 65 is preferably madesumciently light to permit this following movement of the valve member65 to take place so that the parts may be moved by operation of the mudpumps into positions such as that illustrated in Fig. 7. When thisposition is reached by the parts, the valve spring 65 is compressedsubstantially to its upper limit and it is necessary, in order that thedesired upwardly directed blow be 55 struck by the jar, to at this pointopen the valve 66 substantially instantly. I therefore provide a pushrod or valve opening member 15 which is disposed within the bore 14formed through the hammer 60, the push rod 15 carrying at its lower toend an annular flange portion 16 adapted to rest upon a smallcompression spring I1.

The compression spring I1 may be housed within an enlargement. 18 of theaforementioned wash opening 51 which is provided in the lower adaptor 6555, the lower end of the compression spring 11 being rested upon ashoulder 19 which is formed at the Junction of the wash opening 51 andthe enlargement 18 thereof. The flange portion 18 is preferablyapertured as indicated at 80 in Fig. 70 7a to provide a fluidinterconnection between the interior of the housing 50 and the washopening The spring constants of the valve spring 5 and the push rodspring 11 are preferably so adjusted that when they are exerting theirmaxiupwardly directed force upon a valve member $8.

mum combined force, such force is insufliclent to eflect an opening ofthe valve 88. when the; springs are thus adjusted, the simultaneousdownward movement of the hammer 80 and the valve member 88 will continueuntil the valve member 88 engages the upper end of the push rod 18 atwhich time the push rod 15 will also be moved downwardly with the valvemember 88. This downward movement of the push rod will continue untilthe adjacent turns of the helical spring 11 are brought into engagementwith each other, at which time further downward movement of the push rod18 is positively prevented.

The relative positions of the parts at the time the downward movement ofthe push rod 18 is arrested is illustrated in Figs. 7 and 7a. When theparts occupy these positions, continued operation of the mud pumpsserves to force the hammer 80 downwardly an additional small distance.Because such movement of the hammer 80 is permitted while furthermovement of the valve member 68 is positively prevented by the push rod15, the valve member 88 will be slightly raised from its seat 13 so asto dispose the parts in positions such as that illustrated in Figs, 8and 841. Such partial opening of the valve causes fluid to flow fromthat portion of the interior of the housing 80 which is disposed abovethe valve 88 into the bore 1,; provided in the hammer 88 with the resultthat the downward force on the valve member 88 is reduced. As soon assuch a reduction in force occurs, the push rod spring 11 and the valvespring 85 serve to impart an upwardly directed accelerating force to thevalve member 88, the spring 11 serving to provide a high accelerationduring the first part of the upward movement of the valve and the valvespring 88 serving to cause a continuation of the upward movement of thevalve to its final upward position such as that illustrated in Fig. 9.Simultaneously with the retraction of the valve member 88, the pressureexerted on the top of the hammer 80 is also released with the resultthat the compression spring 59 immediately starts the hammer 88 in acontinuously accelerating upward movement. The movement of the hammer 88is arrested by engagement of the striking portion 8| thereof with theanvil 82 at which time a severe upwardly directed impact is transmittedto the fish.

In order that this operation may take place, it is necessary that themass of push rod 18 and the valve 88 be so adjusted with respect to theforce which is exerted by the spring 85 and 1.1 as to cause the valvemember 88 to accelerate at a higher rate than does the hammer 80 inorder to permit the valve member 86 to be completely retracted beforethe hammer 88 is moved to impacted position. It will be observed byhaving reference to Fig. 6 that as soon as the blow is struck, the valvemember 88 again occupies a closed position relative to its seat 18 sothat continued operation of the mud pumps will cause a repetition of theabove described cycle.

It will be appreciated that with the above described embodiments of minvention, the valve member 88 will be abruptly closed as soon as thejarring blow has been struck by the hammer, with the result that aconsiderable water hammer" will be produced. Such a water hammer causesextremely high pressure to be momentarily produced with the attendantpossibility of injuring the joints in the drill string between the jarand the ground surface.

Such water hammer may be prevented by employing an additional refinementconstructed which is extended downwardly from the upper along the linesillustrated in Fig. 10. The pressure developed the instant the valvemember 88 closes may be relieved by providing a fluid bypass around thevalve member 88. As is illustrated in Fig. 10 this by-pass mayconveniently comprise a longitudinally extending bore 8| surface of thehammer 88, the bore 8| being extended into communication with theinternal bore 14 or the hammer 88 by means of one or more laterallyextending bores 82 which are extended between the bore 14 and the bore8|. 'ihe bore 8| is preferably enlarged as indicated at 88 to define ashoulder 84 against which a compression spring '88 may rest. Thecompress sion-spring 85 serves to urge a ball valve member 88 upwardlyinto engagement with a seat member 81 which may be secured as by meansof threads 88 within the upper end of the bore 83.

The cross sectional area or the seat member 81 and the spring constantof the valve spring 85 are so adjusted as to maintain the ball valvemember 88 closed when the fluid pressure exerted on the upper end of thehammer 88 rise; to a value suilicient to force th hammer to itslowermost position. but are so adjusted as to cause an opening of thevalve should the fluid pressure exceed this operating value by anysubstantial amount. By so adjusting the pressure at which the valve 88opens, water hammer will be prevented at'the time the main valve member88 closes for the reason that the abrupt rise in pressure produced bythe closing of the valve member 88 will cause the valve member 88 toopen the by-pass around the valve member 88 and thus relieve thepressure which is developed on the upper side of the valve member 88.This relief will prevent the momentary increase of pressure on the upperside of the valve member 88 from reaching a sufliciently high value toproduce the undesired effects of a water hammer.

I have also illustrated in Fig. .10 an alternative arrangement foreffecting the opening of the valve member 88 at the time the hammer 88is moved to its lowermost position. It will be noted that in theconstruction illustrated in Fig. 10, the push rod 15 and its spring 11are omitted. The functions of these two elements may be retained,however, by so adjusting the proportions of the valve spring as to causeadiacent turns thereof to come into abutting relation with each other atthe time the hammer 88 is moved to a point closely adjacent itslowermost position. When this condition obtains further downwardmovement of the valv member 88 will be prevented, with the result thatadditional downward movement of the hammer 88 will break the fluid sealat the valve member 88 and permit upward movement of the valve memberand the resulting operation of the device in the manner previouslydescribed.

When this form of construction is employed, the valve spring 88 shouldbe made with suillcient stiifness as to p uce a higher acceleration ofthe valve member 88 than is imparted to the hammer 80 so as to preventthe hammer from overtaking the valve member during upward movement ofthe hammer.

The ball valve and by-pass construction just described may beincorporated in the valve member 88 if desired by employing aconstruction such as that illustrated in F18. 11. As is illustrated inthat figure, the head of the valve membar 66 is elongated in an axialdirection to provide a cylindrical head 90. The-increased length of thehead 90 may be accommodated by providing a skirt portion 9| on the upperadaptor 52 so as to dispose the anvil 82 thereof at a somewhat lowerlocation than in the form of the invention illustrated in Figs. 6through 9a. The valve head 90 is: preferably provided "with an upwardlyextending ,longitudinal bore 92 which is providedwith a reduced diameterex- 10 tension 93 thereof; extended into communication with'the spaceabove the hammer 60 as by means of a fluid passage 94. The extension 93serves as a valve seat foraball valve member 95 which may be urgedthereagainst by means of a compression spring 98 supported upon abushing19'| threadedly secured within the lower end of the". bore 92.

It will be observed that this structure functions in the same manner asthe modification 20 illustrated in Fig. 10, the valve member 95 beingmoved to an open position as soon as the pressure which i exerted uponthe upper end of the hammer B0 rises to a predetermined maximum value soas to prevent a water hammer '25 from being produced by the closing ofthe valve 66.

I have also illustrated in Fig. 11 an additional refinement which may beincorporated in this and in the other modifications of myinventiori'flao" previously described and consisting in the provi- Asion of an orifice for limiting th rate at which fluid may be suppliedto the interior of the housing within which the hammer is mounted.jIfhis orifice may be provided by employing afheanf. which may comprisea cylindrical plug member 98 externally threaded as indicated at 99 topermit its being secured within a correspondingly threaded bore formedin the upper portion of the tool joint half 52. The "bean" or plug B8 is40' provided with a small diameter longitudinally ex--- tending bore I00adapted to permit the passage of drilling fluid downwardly into thechamberldefined by the housing. It has been found that the provision ofsuch a device as the bean 98 or other fiow limiting means serves topermit the pressure above the hammer to be lowered to a substantiallylower value when the jar mechanism is tripped than is the case when sucha flow limiting device is not employed, and also serves to reduce therate of flow of fluid past the hammer during upward movement thereof toa-sufficiently low value as to materially reduce the fluid drag on thehammer and thus permit thedevelopment of the maximum impact on theanvil.

Another useful function which may be ascribed to the flow limitingdevice is that of slowing down the operation of the jar so that theblows which are struck by the hammer will be spaced apart. whereas, ifthe bean is not employed, it may be found that the blows delivered bythe jar will occur in very rapid succession particularly where the slushpumps employed are high speed and large capacity pumps.

It is intended that the bean 98 or other similar 5 flow limiting meansbe employed with the previously described modifications of my inventionas 5a, inclusive.

From the foregoing it will be observed that I have provided a jarconstruction by means of which a constant and undi-minished upwardlydirected force may be exerted on a fish with which the jar is engagedand that this force may be maintained while repeated upwardly directedjarring blows are also exerted on the fish.

It will be noted furthermore'that the jarring action of the device of myinvention is controllable from the ground surface by the control of.

the mud pumps; that is, that th jarring action may be started by thestarting of the mud pumps and may be continued for as long a time as is,desired and may be stopped by merely stopping the mud pumps.

It will also be observed that .I have provided; in the jar of myinvention two types of control equipment for controlling the jarringaction of the jar, the first form of the invention described herelnabovebeing provided with a pressure responsive means for releasing thecompression spring to al-:

low that spring to force the hammer upwardly to develop the jarringblow,.whil the second form of the invention described hereinbefore isprovided with a displacement responsive device which is responsive tocompression of the spring a pre- While I have shown and described thepreferred embodiment of my invention, 1. do not desire to be.

limited to any of the details of construction shown or described herein,except as defined in the appended claims. I claim: 1 I 1. In a jar fordelivering upwardly directed impacts to a fish stuck me. well bore, thecombination of: a strain member adapted to be inserted in said well boreand attached to said fish;

and having an anvil thereom hammer means mounted for retracting movementaway from said anvil and for striking movemenj j nto impacting relationtherewith for imparting upwardly directed impacts to said anvil; meansnormally urging said hammer toward impacting position; means forapplying a force to said hammer to move said hammer. away from saidanvil; and tripping means responsive to a predetermined resistance tosaid letracting movement for removing said force from saidhammer,whereby said hammer is moved into impacting relation with said anvil.

2. In a jar for delivering upwardly directed impacts to a fish stuck ina well bore, the combination of: a strain member adapted to be-in-'serted in said well bore and attached to said fish and having an anvilthereon; hammer means mounted for retracting movement away from saidanvil and for striking movement into impacting relation therewith forimparting upwardly directed impacts to said anvil; means normally urgingsaid hammer toward impacting position; means for applying a force tosaid hammer to move said hammer away from said anvil; tripping meansresponsive to a predetermined resistance to said retracting movement,

for removing said force from said hammer, whereby said hammer is movedinto impacting relation with said anvil; and means responsive to arrivalof said hammer at impacting position for re-setting'said tripping meansto re-apply said force to said hammer.

8. In a Jar ior delivering upwardly directed impacts to a fish stuck ina well bore, the combination of: a strain member adapted to be insertedin said well bore and attached to said fish and having an anvil thereon;hammer means mounted for retracting movement away from said anvil andfor striking movement into impacting relation therewith for impartingupwardly directed impacts to said anvil; means normally urging saidhammer toward impacting position;- means for applying a force to saidhammer to move said hammer away from said anvil; and tripping meansresponsive to retracting movement of said hammer a predetermineddistance for removing said force from said hammer, whereby said hammeris moved into impacting relation with said anvil.

' 4. In a Jar for delivering upwardly directed impacts to a fish stuckin a well bore, the combination of: a strain member adapted to beinserted in said well bore and attached to said fish and having an anvilthereon; hammer means mounted for retracting movement away from saidanvil and for striking movement into impacting relation therewith forimparting upwardly directed impacts to said anvil; means normally urgingsaid hammer toward impacting position; means for applying a force tosaid hammer to move said hammer away from said anvil; tripping meansresponsive to retracting movement of said hammer a predetermineddistance for removing said force from said hammer, whereby said hammer imoved into impacting relation with said anvil; and means responsive toarrival of said hammer at impacting position for re-setting saidtripping means to re-apply said force to said hammer.

5. In a jar for delivering upwardly directed impacts to a fish stuck ina well bore. the combination of: a housing adapted to be inserted in awell bore and attached to said fish and including means for attachmentto a conduit extending from the ground surface and into communicationwith the interior of said housing; an anvil carriedby the upper end ofsaid housing; a. piston-like hammer mounted in said housing for slidablemovement toward and away from said anvil; spring means for normallyurging said hammer into engagement with said anvil whereby the supplyingof fluid under pressure to said housing through said conduit moves saidhammer away from said anvil against the urging of said spring means; andtripping means actuable in response to rise of fluid pressure in saidhousing to a predetermined value to establish a fluid connection throughsaid hammer to release the fluid pressure whereby actuation of saidtripping means permits said spring means to move said hammer back intoengagement with said anvil to impart an upwardly directed impact to saidfish.

6. In a jar for delivering upwardly directed impacts to a fish stuck ina well bore, the com bination of: a housing adapted to be inserted in awell bore and attached to said fish and including means for attachmentto a conduit extending from the ground surface and into communicationwith the interior of said housing; an anvil carried by the upper end ofsaid housing; a piston-like hammer mounted in said housing for slidablemovement toward and away from said anvil; spring means for normallyurging fiuid connection through said hammer to release I the fluidpressure whereby actuation of said tripping means permits said springmeans to move said hammer back into engagement with said anvil to impartan upwardly directed impact to said fish.

'7. In a jar for delivering upwardly directed impacts to a fish stuck ina well bore, the combinationof: a housing adapted to be inserted in awell bore and attached to said fish and including means for attachmentto a conduit extending from theground surface and into co municationwith the interior of said housing; an anvil carried by the upper end ofsaid housing; a piston-like hammer mounted in said housing for slidablemovement toward and away from said anvil; spring means for normallyurging said hammer into engagement with said anvil whereby the supplyingof fluid under pressure to said housing through said conduit moves saidhammer away from said anvil against the urging of said spring means; andtripping means actuable in response to rise of fiuid pressure in saidhousing to a predetermined value to establish a fluid connection throughsaid hammer to release the fluid pressure whereby actuation of saidtripping means permits said spring means to move said hammer back intoengagement with said anvil to impart an upwardly directed impact to saidfish; and means coacting with said tripping means and responsive tomovement of said hammer into engagement with said anvil to actuate saidtripping means to close said fluid connection and permit said hammer tobe again moved away from said anvil.

8. In a jar for delivering upwardly directed impacts to a fish stuck ina well bore, the combination of: a housing adapted to be inserted in awell bore and attached to said fish and including means for attachmentto a conduit extending from the ground surface and into communicationwith the interior of said housing; an anvil carried by the upper end ofsaid housing; a pistonlike hammer mounted in said housing for slidablemovement toward and away from said anvil; spring means for normallyurging said hammer into engagement with said anvil whereby the supplyingof fluid under pressure to said housing through said conduit moves saidhammer away from said anvil against the urging of said spring means; andtripping means actuable in response to rise of fluid pressure in saidhousing to a predetermined value to establish a fluid connection throughsaidhammer to release the fluid pressure whereby actuation of saidtripping means permits said spring means to move said hammer back intoengagement with said anvil to impart an upwardly directed impact to saidfish; and means coacting with said tripping means and responsive tomovement of said hammer into engagement with said anvil to actuate saidtripping means to close said fluid connection and permit said hammer tobe again moved away from said anvil.

9. In a jar for delivering upwardly directed impacts to a fish stuck ina well bore, the combination of a housing adapted to be inserted in awell bore and attached to said fish and includassav'as v i e throughsaid conduit moves said hammer away tion with the interior of saidhousins; an anvil carried by said housing; a piston-like hammer mountedin said housing for slidable movement toward and away from said anvil:spring means for normally urging said hammer into engagement with saidanvil; means deflning a fluid passage extending from the exterior ofsaid housing to the interior thereof between said hiimmer and saidanvil; valve means normally closing said fluid passage and movable byfluid pressure exerted thereon to a position opening said passage; andmeans for holding said valve in closed position releasable in responseto rise in said fluid pressure to a predetermined value to permitmovement of said valve to open position, whereby the supplying of fluidunder pressure to said housing through said conduit moves said hammeraway from said anvil against the urging of said sprin'g means andopening said valve releases said fluid pressure and permits said springmeans to move said hammer into engagement with said anvil to impart anupwardly directed impact to said flsh.

10. In a jar {or delivering upwardly directed impacts to a flsh stuck ina well bore, the combination of: a housing adapted' to be inserted in awell bore and attached to said iish and including means for attachmentto a conduit extending from the ground surface and into communicationwith the interior of said housing; an anvil carried by said housing; apiston-like hammer mounted in said housing for slidable movement towardand away from said anvil and having a fluid passage extendinglongitudinally therethrough; spring means for normally urging saidhammer into engagement with said anvil; valve means normally closingsaid fluid passage and movable by fluid pressure exerted thereon to aposition opening said passage; and means iior holding said valve inclosed position releasable in response to rise in said fluid pressure toa predetermined value to permit movement of said valve to open position,whereby the supplying of fluid under pressure to saidhousing throughsaid conduit moves said hammer away from said anvil against the urgingof said spring means and opening said valve releases said fluid pressurefrom said anvil against the urging of said spring means and opening saidvalve releases said fluid pressure and permits said spring means to movesaid hammer into engagement with said anvil to impart an upwardlydirected impact to said flsh; and means coacting with said holding meansand responsive to momentum of said valve means at the time oi!engagement of said hammer with said anvil for permitting movement ofsaid valve to closed position and thereafter holding said valve in saidclosed position.

12. In aim for delivering upwardly directed impacts to' a fish stuck ina well bore, the combination of: a housing adapted to be inserted in awell bore and attached to said flsh and including means for attachmentto a conduit extending from the ground surface and into communicationwith the interior of said housing; an anvil carried by said housing; apiston-like hammer mounted in said; housing for slidable movement towardand away from said anvil and having a fluid passage extendinglongitudinally therethrough; spring means for normally urging saidhammer into engagement with said anvil; valve means for closing saidfluid passage mounted for movement relative to said hammer between openand closed positions; and means responsive to movement of said hammer toa position a predetermined distance from said anvil for moving saidvalve to said open position, whereby the supplying of fluid underpressure to said housing through said conduit moves said hammer awayfrom said anvil against'the urging of said sprin and permits said springmeans to move said hammer into engagement with said anvil to impart anupwardly directed impact to said flsh.

11. In a jar for delivering upwardly directed impacts to a flsh stuck ina well bore, the combination of: a housing adapted to be inserted in awell bore and attached to said flsh and including means for attachmentto a, conduit extending from the ground surtace and into communicationwith the interior of said housing; an anvil carried by said housing; apiston-like hammer mounted in said housing for slidable movement towardand away from said anvil and having a fluid passage extendinglongitudinally therethrough; spring means for normally urging saidhammer into engagement with said anvil; valve means normally closingsaid fluid passage and means'and opening said valve releases said fluidpressure and permits said spring means to move said hammer intoengagement with said anvil to impart an upwardly directed impact to said13. In a jar for delivering upwardly directed impacts to a flsh stuck ina well bore, the combination of: a housing adapted to be inserted in awell bore and attached to said flsh and including means for attachmentto a conduit extending {mm the ground surface and into communicationwith the interior of said housing; an anvil carried by said housing; apiston-like hammer mounted in said housing for slidable movement towardand away from said anvil and having a fluid passage extendinglongitudinally therethrough; spring means or normally urging said.

housing in a position extending through said pas-- sage and disposingone end thereof a predetermined distance from said anvil, wherebymovement 0! said hammer and valve to a position engaging said headmember and said push rod arrests movement of said valve'and subsequentadditional movement of said hammer opens said valve to relieve saidfluid pressure and permit said spring to move said hammer intoengagement with said anvil.

14. In a jar for delivering upwardly directed impacts to a flsh stuck ina well bore, the combination of: a housing adapted to be inserted in awell bore and attached to-said fish and including means for attachmentto a conduit extending from the ground surface and into communicationwith the interior of said housing; an anvil carried by said housing; apiston-like hammer mounted in said housing for slidable movement towardand away from said anvil and having a fluid passage extendinglongitudinally therethrough'; spring means for normally urging saidhammer into engagement with said anvil; valve means mounted on saidhousing for movement with said hammer and independently thereof, saidvalve means including a head portion extended across said fluid passage,whereby fluid pressure transmitted to said housing through said conduitwill hold said valve against said hammer and move said hammer and valvesimultaneously away from said anvil against the urging of said springmeans; a push rod supported on said housing in a position extendingthrough said passage and disposing one end thereof a predetermineddistance from said anvil to engage said head member when said hammer andvalve are moved away from said anvil; means mounting said push rod forlimited axial movement in the direction of movement of said hammer toarrest movement of said valve member when said push rod is moved to theend of its limited movement and thereby open said valve upon subsequentadditional movement of said hammer; and accelerating spring means fornormally urging said push rod toward said anvil to accelerate movementof said valve member away from said hammer when said valve is open.

15. In a jar for delivering'upwardly directed impacts to a fish stuck ina well bore, the combination of: a housing adapted to be inserted in awell bore and attached to said flsh and including means for attachmentto a conduit extending from the ground surface and into communicationwith the interior of said housing; an anvil carried by said housing; apiston-like hammer mounted in said housing for slidable movement towardand away from said anvil; spring means for normally urging said hammerinto engagement with said anvil tripping means actuatable in response tomovement of said hammer a predetermined distance away from said anvil toestablish a fluid connection from the exterior of said housing to theinterior thereof between said hammer and said anvil, whereby thesupplying of fluid under pressure to said housing through said conduitmoves said hammer away from said anvil against the urging of said springmeans and actuation of said tripping means permits said spring means tomove said hammer into wardly directed impact to said fish; meanscoacting with said tripping means and responsive to movement of saidhammer into engagement with said anvil to actuate said tripping means toclose said fluid connection and permit said hammer to be again movedaway from said anvil; and a pressure relief valve actuatable in responseto rise in fluid pressure in said housing to a predetermined valuetoestablish a fluid connection from the exterior of said housing to theinterior thereof to prevent water hammer upon re-closing of saidtripping means.

16. In a jar for delivering upwardly directed I impacts to a flsh stuckin a well bore, the combination of: a housing adapted to be inserted ina well bore and attached to said fish and including means for attachmentto a conduit extending from the ground surface and into communicationwith the interior of said housing; an anvil carried by said housing; apiston-like hammer mounted in said housing for slidable movement towardand away from said anvil and having a fluid passage extendinglongitudinally therethrough; spring means for normally urging saidhammer into engagement with said anvil; valve means mounted on saidhousing for movement with said hammer and independently thereof, saidvalve means including a head portion extended across said fluid passage,whereby fluid pressure transmitted to said housing through said conduitwill hold said valve against said hammer and move said hammer and valvesimultaneously away from said anvil against the urging of said springmeans; accelerating spring means for normally urging said valve meanstoward open position; means for arresting movement of said valve means apredetermined distance from said anvil, whereby additional movement ofsaid hammer away from said anvil permits said accelerating spring meansto move said valve to open position and permits movement of said hammerinto engagement with said anvil: a fluid by-pass channel extended fromsaid fluid passage and into communication with the interior of saidhousing at a point disposed between said hammer and said anvil; and apressure responsive valve normally closing said fluid by-pass channeland actuatable in response to rise in said fluid pressure above apredetermined value to open said by-pass channel, whereby water hammerresulting from the re-closing of said valve means is prevented by theopening of said pressure responsive valve.

JOHN '1'. Pumps.

